1. Field of the Invention
The invention relates to a method for installing a bearing in a universal coupling of the so-called Hooke's Joint type. The invention also relates to couplings assembled by this method.
In particular, the Hooke's Joint couplings envisaged here are of the heaviest type of construction, such as those used to drive rolling mills, for example, and whose greatest external diameter, known as the diameter of rotation, can amount to more than one meter.
2. Description of the Prior Art
In known Hooke's Joint couplings of this kind (see, for example, Federal Republic of Germany Auslegeschrift No. 19 14 039), the coupling forks are made in more than one piece, i.e. each fork eye is divided across a diameter, so that one half of the fork eye can be removed from the coupling fork like a bearing cap. This means that the assembly of the Hooke's Joint coupling can be effected by first mounting the complete bearing assemblies (bearing sleeves with their rolling elements, generally rollers, located in them) on the pins of the crosspiece, and then inserting the crosspiece, together with the bearings, successively into the two couplings forks, after which each of the fork-eye halves are bolted to the coupling fork. The installation of the bearings and the assembly of the coupling is thus a relatively simple operation in this case. It is also possible to replace a bearing, for example at the site where the coupling is used, without the entire coupling shaft having to be removed from the drive line.
However, a particular disadvantage of the above described Hooke's Joint couplings lies in the fact that the coupling forks lose much of their rigidity because they are made in more than one piece. There is always a danger that where large torques are being transmitted, the coupling forks will be deformed, and with them the bearing housing as well, consequently reducing the working life of the bearings.
For this reason, attempts have been made to construct Hooke's Joint couplings, even of the largest size, with one-piece coupling forks. However, the installation of the bearings in the fork eyes of the coupling and the assembly of the one-piece coupling must be carried out by radically different means than is the case with Hooke's Joint couplings having split coupling forks. With a one-piece coupling, it is first necessary to insert the crosspiece into one of the coupling forks without the bearings. Then the bearings are pressed in and simultaneously pushed onto the crosspiece from the outside, along a direction parallel to the axis of the bearing. It is already known (from German Pat. Specification No. 15 27 557) for a special pressing-in device to be used for inserting the bearings into the fork eyes. However, the known pressing-in device is unsuitable for use on couplings of the largest size, since the dimensions of the pressing-in device are considerably greater than those of the Hooke's Joint coupling. Naturally, it would also be possible to produce a pressing-in device of this kind for larger size Hooke's Joint couplings. However, such a large size device would have the disadvantages that it would be expensive to construct and it could only be used on the production site during the initial assembly of the Hooke's Joint couplings, while it could not, as a practical matter, be used to replace a bearing at the site where the Hooke's Joint coupling is in service. Since such a device would be extremely large and heavy, it would be impracticable to transport it to the site of the Hooke's Joint coupling installation.